It feels like we should brainstorm a bit more on ideas before we actually decide on which idea we will take on.

Also, it's not that easy for a community to choose an idea. It's not as easy as someone saying "This is what we will do". I'm referring to those who posted something in the line of "Pick an idea already!". I think the best would be to create a poll of all ideas we have or at least pick an idea with several following posts that saying "I agree".

a set of modules so you can make whatever robot you want easily.that way you can make whatever you want and i can make whatever i want. the fact you use a servo controller module to aim and point an airsoft gun while i use it to poke a sharp stick at the neighbours cat does not affect the design of the servo controller module.

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Edit: let's state the communication specs between the modules so we can start building them!

while i was sat board on a plane earlier today i wrote down some notes on the bus architecture of my own robot.i think it is a suitable starting point for the control and communication architecture of the sort of modules we are discussing here.

reading the doc will require a reasonable understanding of the i2c bus i'm afraid. (you can find an i2c tutorial on SOR members pages...)

let me know your opinions as to whether this is a suitable architecture to network our modules.the advantage of using this architecture is i can provide sample circuit diagrams and firmware giving the project a kick start.i will need to rewrite the i2c master code though as it's far from readable but otherwise we would be good to start.

the key to this project being successful i believe will be good documentation of some sample modules so people can modify them without ever having to write their own i2c code.

This will include chassis and such for each module and making fasteners to connect them together, right?

i envisaged the chassis components being separate modules from the electronics modules.

for example someone might design a servo driven pan and tilt chassis module for an airsoft gun.this module would need a servo controller but i would argue the servo controller could be a separate module.

it would have to be documented within the airsoft gun module documentation that it requires the servo controller module and how to connect the 2 together but the servo controller module could still be used as a valid module without the airsoft gun module.space and mounting brackets could be included in the airsoft gun module for which ever servo controller module is used.

i do think it would be a good idea to standardise connections between modules though. mounting holes on circuit boards should be a set distance apart so it's easy to swap one module with another.power plugs should be of a standard type.electrical connectors should be of a standard type.screw sizes should be kept standard whenever possible. (not really possible with metric and imperial countries contributing but still...)we should pick some set voltages for the power bus. (0V, 12V and 5V?)

to be honest i'm more interested in the electronics side of a project like this so i have not put much thought into how to connect the mechanical modules.would a complete chassis design complete with drive units (servos or motors) with room to add lots of other modules count as a module?

What it sounds like we need to do is some standardized designs and make an open source SOR robot design. Sorta like the $50 robot design is part of what gets people into robotics around here and the tutorial stuff is a great help as well. We could then have these modules that are tested and work with a each other but the configuration is up to the builder. So if I want to build a robot that drives around and maps my room then sends that data through a wifi link to my PC, I can take the wifi module, the sensor module, several motor drivers, and a mcu to put it all together and bam I have a working robot.

Then when a newbie comes into the group they start with the $50 robot and the they can slowly build the modules and start getting more advanced robots faster. We could even do group runs of pcbs where someone wants a module and sets up a run then takes orders from everyone else and the cost goes down if you order like 50 or so boards. Then the person who started the run collects the money for them and ships the boards out..

Also we will need a open source programming area as well. Where functions for each module on a pic and avr are already made and you just download the code to go with each one and tie them together with your own code. It has potential but needs to be managed and a good system developed to manage the files and projects.

One small point that i think needs to be added: The modules should be simple enough to be able to solder with a prototyping pcb or even with a breadboard. Many will want to solder the boards on their own and just as many don't have the possibility to etch their own pcb.

The plan seems to have changed, we're not making one robot anymore.Now te plan is to design a whole set of modules (a part of a robot. eg sa motor driver,...) that can communicate with eachother via a protocol called I²C (only 4 wires) .With these plans of modules, everyone can make the amount of modules and the modules of choice to put them together to make a robot easier and faster.

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>very fun and exciting. It should be something big, impressive and advancedThis is doable. I've been pushing for some kind of community project like this in several places...for instance, see http://en.wikiversity.org/wiki/Useful_robots for a description of a machine vision project.

The one thing that may sound strange in my proposal is a sensor that I don't see that anyone has mentioned on the electronics board here at SoR: the "phase-shifting laser rangefinder". Here's a quick description I give over at robots.wikia.com:

There's a new kind of sensor available now. "Phase-shift laser rangefinders" measure distance along a line of sight, and this gives them much better range and accuracy than ultrasonic or infrared rangefinders and proximity detectors. You can find lots of them for less than $100 on Amazon, but I'll just mention the specs on one as an example of what you can get for around $130: the Bosch DLE50 (http://www.bosch-pt.com/productspecials/blue/dle50/gb/en/function/index.htm). Note: I haven't bought this and I have no opinion about it, they just have the most descriptive website (you get to play with the buttons). It's tiny (175g or 6 ounces, including batteries), has a range of 5cm to 50m (2 inches to 55 yards), and is accurate to within 1.5mm (0.06 inches) at a range of 30m or less. Lasers are notorious battery drainers, but that's not a killer: you can use other sensors until you need the greater accuracy and range. An annoying caveat is, I haven't yet found a cheap one with a data port, and the only one I've found with Bluetooth is over $600. But I expect this flaw will be remedied soon.

>Maybe connect the robots to the internet...just add a wireless communication module

A group can trade advice on building robots, but for people who can afford the wireless link, that really makes it much more of a group project...we could drive and see through each other's machines, process the images, use AI to determine behaviors, etc. This also means that people who have no money to spend at all could still participate on the web. Since my interest is machine vision, it's not so important to me what the robot can do...only that it's holding some kind of rangefinder or camera and sending the images to the web.

Actuator modules:- complete actuator sets, like a whole 3-DOF leg (including a control system that takes 3D positions as parameters and turns them into angles on the servos)- pan/tilt modules able to get data directly from sensor or vision modules?

Communication modules:Not a specific module, but it would be cool if the parts on the other side of the communication would be treated the same way as the own modules. Could result in cool behavior if two of these modular robots is communicating.

These are just my first thought ideas. Theres a lot more to come i guess.

I wonder where Admin is. Seriously if he hasn't posted because he's been trying to fix the forum and site for us I'm going to cry. Admin take a break! We're not even going to get 0.0000000000000000000000000000000000001% angry if something doesn't work even if we sent you an email.

What if we made like a donation button on the website which you could put on your website. It would circulate to many places. For example if 500 member gave a misery dollar, that's still some money. I think everybody is in debt to Admin for making this website. I mean why don't you try and name a member who hasn't learned something from this site. (Don't try, you'll get a headache.)

I am sorry, but I am not very clear in how much this stuff costs. Approximately how much will it cost depending on:

1) Some people are willing to donate some parts that they have. (minimum)

2) Nobody donates anything and every part must be bought. (maximum)

This is like the only website specializing on ROBOTICS, not just instructables with like 5 tutorials. This is like a whole database with tons of information, so with a good letter, we might be able to convince some company to sponsor this project.

We don't really need to worry about money right now! We need to get this project rolling first. We need a new forum for this project, some more brainstorming on ideas, have a finished design model of communication and such before we can start building anything physically and thereby put out any money.

Also, is it that expensive. The whole idea of a community project is that the work is spread out over all members. That also includes the costs. How much could it cost you to develop a module? I'll easily put out $50, $100 or even more so for this project. Thats completely ok to me. However, we should try to get sponsorship in some way. It's just that we shouldn't worry about that now and concentrate on getting forward on this project.

I'll send an email to Admin and see if he could add another forum for the project.

So every module we'll make will have an embeded microcontroller with connectors for sensors or motors. The connection to the main MCU being I2C serial interface.

What microcontroller shoud we use? I think we need to have one specific for the task of the module.For instance, the motors module could have a ATtiny26, an H bridge and connectors for motors, encoders and power. The sensors module could have a ATmega8 and connectors for sensors. The servo controller module could also have a ATmega8 or a more appropriate one, depending on the number of servos needed. If someone finds it easier to work with PICs no problem, but it should use a programmer easy to make and free software to upload the firmware.

We should discuss every module apart. That means create a thread for each module in the Electronics section of this forum. Like Dunk said, we need to use standard size and connectors so modules can be interchangeable (for instance DC motors module with servo module). Also standard comunication protocol for all of them.

This is like a Lego modules kit to build any kind of robots. Heh, if one wants, he can enclose the modules in Lego bricks and use Legos to build the chassis. Anything is possible.

I think if the modules will be well worked and documented, someone like SparkFun may even consider to build and sell them.

Thinking about Admin's Axon, I see it as an (almost) All-In-One solution, a verry simple and powerfull solution for anyone's needs. But sometimes, modularity may be usefull, so this project is a perfect viable solution. The advantage of a modular solution is multitasking. If Admin (or anyone else for that matter) will be able to provide an multitasking language for Axon, that will be the most affordable solution. But even Axon needs the DC motor module and comunication modules.

I sent a PM last night to admin asking about a forum category for this project.

He said that he'd been busy but he promises to look into it soon.I too wouldn't mind spending a bit of money developing a module either. I get to keep what i develop so it not a problem.

Thanks, now i don't need to do it Usually takes a lot of time for me to write an email or PM.

And yeah, thats what i like about this project so much. Everything you develop can be used for further projects instead of just one time like on most project (if you don't tear apart your project you put so much time and effort into of course).

I've found that ATmega168 is almost as cheap as ATmega8. With the memory improvements on the 168 I'm not so sure which would be to prefer. Which brand is easier to get hands on? AVR or PIC? I've found that PIC is more common in electronics shops (well, the only Chain store with hobby electronics i know of, Kjell & Co, only sells the PIC microcontrollers). Although personally i like AVR more.

I think we should come up with a standard dimension for the boards, so that brackets with the same dimensions could be designed. Preferably square formed, right? That means you can put the boards in four different directions to get wires and such in the preferred direction. Admins Axon is square shaped, right? what if we would go with those dimensions. If one board needs more space, we'll build on the height. with layers of pcb.

I think we should come up with a standard dimension for the boards, so that brackets with the same dimensions could be designed. Preferably square formed, right? That means you can put the boards in four different directions to get wires and such in the preferred direction. Admins Axon is square shaped, right? what if we would go with those dimensions. If one board needs more space, we'll build on the height. with layers of pcb.

Yes, square looks good. We should also decide if we want to make a Main MCU module or use Admin's or one of the allready available solutions.

The modules may be stackable, with the comunication connectors plugged from one layer to the other, top-down. With the Main MCU on the top, plug the other modules underneath and fix them with standoffs. The modules will need then horisontal connectors for sensors and motors. Or, if one needs to install them in different places on the robot, wires may also be used.